Dearomative pyrrole (3+2) reaction with geminal bromonitroalkane: synthesis of 2,3-dihydropyrroles.

Dearomative 1,3-dipolar cycloadditions of 1-Boc-pyrroles with in situ generated silver α-bromo alkylidenenitronates delivered a series of 3 a ,6 a -dihydro-4-Boc-pyrrolo[2,3- d ]isoxazole-2-oxides (17-91% yields) under very mild conditions. N -Deoxygenation of the cycloaddition product gave a dihydro-pyrrolo[2,3- d ]isoxazole, elaborations of which produced various functionalized 2,3-dihydropyrroles and pyrrolidines, showcasing the potential utilities of our new strategy of pyrrole dearomatization.